Main advantages of the banking system, utilizing the said credit card are as follows:
a. The card is simple and inexpensive in production.
b. The card and approving device are universal and simple in use.
c. The card, being devoid of any surface information, provides the unambiguous, automatic, real-time authentication and verification of the user. The probability of accidental misuse is no higher then 10.sup.-7 .
d. The card is absolutely foolproof from stealing.
e. In combination with the suggested techniques the system becomes absolutely protected from forging, even if the principle of the card protection is known. The forging can be realized with information from the bank computor memory only.
f. The approval device is small, self-consistent, universal and unexpensive. Being realised in the form of solid-state optics, it can be incorporated in all the applications, including even personal phone-sets, paid-phones, bar-code counters, etc.
g. The card can include the additional sheltering information of any degree of graphical complexity. Said information doesn't affect either time or complexity of the card itself, the approval device, or authorization time.
h. All the approval procedures in all the applications are absolutely automatic and the existing communication channels/lines for banking information are being utilized.
Fingerprint being the most representative and informative natural object numerous attempts were made to incorporate it in recognition devices.
Some number of correspondent inventions and patents exist, some of them recently granted.
The said patents can be divided into two main categories: with computer correlation and with elements of optical processing.
Devices from the secondary category even include in some cases coherent sourse of illumination (see, for instance, Hartwig Ruell, U.S. Pat. No. 4,532,508).
In the computerized recognition systems with fingerprint as the approval element (see, for instance, Arthur B. Carrol, et al., U.S.Pat. No. 4,684,801) the input fingerprint is usually introduced to the display window and scanned. The scanned data is then directed to the processor and compared with the set of fingerprints, already being stored.
One should realise that the informational volume for such informative object as fingerprint usually demand all operative memory of processor. So the prestored fingerprints use the long-time storage media (discs, tapes, etc), needed data being introduced on demand. Corresponding time lapses exist even for the most powerfull computers and are usually not mentioned in these patent claims.
In some of the patents the elements of coherent processing are indirectly used, even for the credit card approval (see Paul B. Elmes, U.S. Pat. No. 4,455,083), though in them the said elements are utilized in fingerprints superimposing only, the advantages of Fourier spectra analysis not incorporated.
In all the recently claimed of these patents the main problem of authentication--positioning of fingerprints--is silently realised. Inventors are trying to bypass it with the variety of different means, including the rotation of light source (Paul A. Hakenewerth, U.S. Pat. No. 4,684,802), scanners of different levels of complexity (see Robert F. Bunn, U.S. Pat. No. 4,641,350), means for mechanical rotation of the fingerprints, and even including the grooves for input fingerprint positioning.
It should be noted here, that for computerized systems, the said positioning of the fingerprints is being realized electronically, each new position of the input fingerprint being treated as the new input object. This either increases greatly the processing time, or--the rather elaborate and time consuming algorithms are being incorporated.
In the mostly recent granted patents, utilizing the holographic storage and even the "modulated reference wave", (see U.S. Pat. Nos. 4,532,508, and 4,385,831) the possibilites and advantages of coherent processing are not employed, correlation procedures not being optically incorporated.
The task being very attractive, some optical systems utilize the fiber-optics elements (Robert F. Dowling, U.S. Pat. No. 4,785,171) and, independently the patents for non-optical fingerprint recognition systems exist (see Otmar Kern, U.S. Pat. No. 4,541,112; David G. Edwards, U.S. Pat. No. 4,429,413).
All the mentioned disadvantages are being eliminated in the system under claim. Due to application in it by the very simple and real-time procedures, the spatial invariance and multi-step fully optical correlation procedures are incorporated.
The system under claim uses for synthesizes the previous numerous publications of the inventor (see, for instance J. S. Barbanell, Analysis of optical correlator for fingerprints, Papers of Institute of Radioengineering, p.202, 1972, Leningrad; J. S. Barbanell. Autometry, #5, 14, 1975, J. S. Barbanell et. al, invention certificates: #312,282, 1968, Lenseless Optical Correlator for Fingerprints, #528,605 and 528,611 (1980)-Coherent Matched Filter with Optical Feedback).